Voltage variator control



July 3, 1951 H. E. cARsoN 2,559,277

VOLTAGE VARIATOR CONTROL Filed Oct. l2, 1948 :L mal Patented July 3, 1951 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to a voltage variator control for loads, the service of which is variated by volt variation. One broad example of such variable service is a multi-speed fan and the speed thereof is determined by variation in voltage applied to the motor terminals. Such a fan motor, in many instances, is or" the shaded pole type, series or universal type or permanent capacitor type although the motor may be of other types. The present voltage variator also has some phase variation included therein. Mention of the motor type of load is not to be considered at restrictive, but merely illustrative of one load, the service of which can be varied by the present invention by primarily varying voltage applied to that load from a relatively constant voltage supply.

The present invention also provides a specific series voltage dropping arrangement. When the invention is applied to fan motors for speed control purposes all the desirable objectives of minimum low speeds with minimum noise is obtained. The present invention is further characterized by the substantially continuous voltage variation throughout the range of the invention.

The chief feature of the invention, therefore, resides in the attainment of the voltage dropping characteristic inherently obtainable from the potential variator herein disclosed.

Other objects and features of the invention will be set forth fully hereinafter.

rPhe full nature of the invention will be understood from the accompanying drawings and the following description and claims.

In the drawings- Fig. 1 is a perspective View of the one embodiment of the invention looking toward the socalled jumper side thereof.

Fig. 2 is a front view looking at the manual control side thereof.

Fig. 3 is a schematic wiring diagram of the invention.

Fig. 4 is a schematic Wiring diagram of a second embodiment of the invention.

In the drawings I indicates a plurality of L- shaped laminations. These are assembled together in hollow core form and are retained in that position by bolts and nuts II. These bolts simultaneously anchor two U-shaped strips I2 and I3 which extend across, as it were, a gap or central hole in the core, but the same are spaced from the ends of the hole and are oppositely disposed relative thereto.

Disposed in this hole is a shaft I4 and mounted on the forward projecting end of this shaft,

(Cl. Mln-119) 2 which is rotatably mounted by the central portions of these U-shaped strips, is a control knob or handle I5.

The oppositely disposed L-shaped laminations when assembled form two parallel legs of said,

core. Upon each of these two parallel legs of the core there is mounted a coil I6. This may be of single layer type, but may, as shown herein, be and same preferably is of multiple layer type. For purposes of illustration two layers |641 and |617 are shown and these may be suitably insulated, that is layer from layer as indicated at Iiic. The outer layer of Wire preferably is of wire suitably japaned or the like for insulation purposes.

The shaft I4 carries inwardly of the strip or stirrup I2, an insulation member I'I and carried thereby is a central conducting member I8a, having iingers I8 that at their free ends terminate in indented portions |8121. These fingers are of spring type and are normally under tension and engage the adjacent face of the cute-r winding of the respective coils forming thereon the arcuate path I9.

The shaft I4 is square in cross section and the hole in the insulation member Il is also square. Adjacent thereto is a disc 2i] and the same has the shoulders 26a on the edge thereof. This disc 26 also has a square hole for shaft mounting. The strip l2 is either apertured or indented as indicated at 22 and a pair of balls 23 are adapted to be seated in said seats 22 and also in the seats 24 formed in the disc 26. The strip I2 includes an inwardly extending tongue portion 25 and this is adapted to selectively engage the shoulders Zta, when the shaft I4 is moved to one extreme position of oscillation or the other eXtreme position. When the ball seats 22 constitute holes there is provided a strap spring 2S having a central opening to accommodate the shaft l5. This spring has reduced ends 21 engaging in offset sockets 23 struck from the strap or stirrup l2. Thus the spring 26 normally constrains the balls into engagement position with the plate 2Q and serve to hold the shaft in its rotated position.

The balls, when registering with opposed pairs of seats 24 in said disc yieldingly lock the jumper in one of the two positions, off or high," but permit forcible movement of the jumper I8 to any selected position.

Reference will now be had to Fig. 3. Herein there are indicated two power supply lines 30 and 3 I. The line 30 may be extended to the load. There is a third line 32 that also is connected to the load. If desired, lines 30 and 32 may be connected to the supply and lines 30 and 3l connected to the load. The inner layer coil in Fig. 3 is designated by the numeral 33 and is connected at one end as at 34 tothe line 3l. Its opposite end 35 is connected to one end of the outer coil 36, the other end of which is open. Adjacent thereto is a short coil S1, having one end open and the other end connected by line 38 to the end of coil 33 at 34 as shown.

The other` coil structure is similar but reversely disposed and contemplates the inner coil 39, having one end connected at 46 to line 52. lts other end is connected to one end of the outer coil 42. The other end is open. Adjacent thereto is the short coil d3, having one end open and the other end connected by line 4 to the junction ll and therefore line 32.

The jumper is indicated in this Fig. 3 by the numeral iii and the contact portions are similarly indicated by the arrow portions i613. When the jumper is disposed in the dotted line portion indicated by the letter a: there is an open circuit arrangement and therefore the load does not receive any energy from the supply. When the jumper is disposed as illustrated by the full line in Fig. 3, it will be noted that substantially all of the inductive resistance is shorted out and the load is substantially across the line and, therefore, is subjected to full voltage. When the jumper is disposed as indicated by the dotted line y substantially all the inductive resistance is included and, therefore, the load is subjected to minimum voltage within the range of the control that can be impressed by this voltage variator.

It will be observed that this variator is of series type and is eiective simultaneously upon each inductive resistance to decrease or increase the eiect thereof, thus increasing or decreasing voltage dropping effect. When a single layer coil is applied to each leg obviously the coil 93 and the coil 39 will be omitted and then the coil 42 will be directly connected with junction 49 and the coil 36 will be directly connected to junction 34.

If three coil layers are employed they may be wound for added inductive or compensating inducting effect and they will be connected in series between junction 34 and line 95 and junction 49 and line 4l.

The present invention, therefore7 is capable of a wide range modification and is extremely compact and it presents, by virtue of the winding a1'- rangement, the erect of a considerable linear resistance construction.

In Fig. 4 there is illustrated a slightly modified form of the invention. This form is utilized as a Vernier device to obtain an output voltage above or below line voltage from a substantially constant voltage source.

Herein lines and 5l may represent the supply lines and 52 and 53 the load lines. Thus as before one line may be direct from line to load. As before inner and outer layers of coils are employed. Inner layer 54 connects to junction 55 at one end and its other end is connected by line 56 to one end of inner coil 51, connected at its other end to junction 58.

This junction connects by line 59 to center tap 60 or outer coil 6|. Line 53 connects to center tap 62 of outer coil 63. As before jumper I8 has contacts ita and Ib. When jumper i3 has its contacts 19a and I8b coincident with center taps 65 and 62 respectively line voltage is impressed upon the load. As the jumper is moved therefrom the voltage impressed upon the load is greater or less than line voltage.

While the invention has been illustrated and described in great detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The several modifications described herein as well as others which will readily suggest themselves to persons skilled in this art, all :are considered to be within the broad scope of the invention, reference being had to the appended claims.

The invention claimed` is:

1. A voltage variator comprising a pair of concentricv coils, a second pair of concentrick coils, line terminals, load terminals and oscillatable nger for each outer coil and arranged i'or wiping electrical contact with the insulated turns thereof, means electrically connecting the fingers together, means for simultaneously moving both iingers, and core means within each pair of concentric coils, one load and one line terminal having direct connection, and the other line and load terminals having connections to one end or the inner coils, one position of the fingers effecting line voltage application upon the load.

2. A voltage variator as defined by claim 1 wherein each outer coil includes an intermediate tap, one having direct connection to a load terminal and the other to a line terminal,

3. A voltage variator as dei-ined by claim 2 wherein the taps are medianly disposed.

4. A voltage variator comprising a core formed of a plurality of internested, L-shaped laminations providing spaced apart leg portions and end portions, a coil layer wound on each leg portion, a bridging member spaced from said core structure, having its opposite ends secured to the opposite end portions, a shaft rotatably supported on said bridging member, an insulating support mounted on and rotatable with said shaft and a pair of wiping contact lingers electrically connected carried by said insulating member and having their ends respectively in wiping contact with the respective coils o'n the leg portions.

HAROLD E. CARSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

